As far as gcc is concerned, the "z size specifier" is available as
an extension to the language, which is available with or without any
-std= switch.  (I think you have to go back to 2.95 for a version
of gcc which doesn't work.)  Many other compilers have this as an
extension as well (ie without the equivalent of -std=c99).

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>